Colorado voters just made it a lot harder to pass fracking bans.

In recent years, a number of communities in the state have passed local bans, but the state Supreme Court struck them down. Activists then decided to try to change the constitution to allow local fracking bans. So the oil and gas industry then decided to try to make changing the constitution more difficult.

The oil and gas industry insists the amendment is an attempt to ensure only initiatives that are “constitutional-worthy” gain consideration by voters. But anti-fracking activists say it’s a just a way to make citizen campaigns less likely to succeed.

Campaigners still hope to run another ballot measure to legalize local fracking bans in 2018, but after Tuesday’s vote, that will be trickier than ever.